The present invention relates generally to compressors, and more particularly relates to mufflers for reducing noise in compressors.
Existing compressors, such as air conditioning compressors found in vehicles, are relatively noisy. Accordingly, many compressors include a built-in flow noise control device or muffler. Unfortunately, these devices are usually a bulky addition to the compressor casting or housing, increasing the overall size and mass of the compressor significantly. Furthermore, these mufflers typically communicate with the discharge flow or the suction flow through a long and narrow passage. This passage is strictly a communication channel, and does not direct flow in a manner that effectively utilizes the interior of the muffler. One drawback includes a large flow loss due to the structure of the communication channel. Flow loss refers to a pressure loss in the flow due to the restricted flow passage. The more flow loss, the more power is required to compress same amount of refrigerant through a passage. Therefore, there exists a need to provide a muffler for a compressor that not only reduces the flow loss through the muffler, but which also reduces the overall size, weight and cost of the compressor.
The present invention provides a muffler for a compressor that is incorporated into the existing rear housing portion of the compressor housing. In this way, the present invention provides a compressor which has reduced size and weight compared to existing compressors with external mufflers, mufflers as well as reducing the amount of flow loss. In turn, the efficiency of the compressor is increased (i.e. lower power consumption) due to streamlined flow with less turbulence. Additionally, the integral muffler adds stiffness to the rear housing that attributes to lower vibration. Preferably, a muffler chamber is defined within a discharge chamber, and the discharge chamber is further sub-divided into first and second portions. Discharge flow entering the first portion of the discharge chamber must flow through the muffler chamber before reaching the second portion of the discharge chamber for exit through a discharge port. Generally, the muffler chamber is defined by a muffler wall which includes restrictions to regulate the flow from the first portion to the second portion of the discharge chamber. Additional features include further subdividing the discharge chamber into several smaller cavities, as well as providing high pressure fluid directly to the second portion and discharge port.